Recycled Mortars with C&D Waste

Nowadays an environmental problem that cannot be underestimated is the increasing amount of waste of different nature. Certainly, an environmental friendly solution is to use waste directly or indirectly in the production of concrete or mortar, which are the most used building materials in the world. In the production of coarse recycled aggregates (RA), the fine fraction, also called recycled sand (RS), is involuntarily produced and it represents a large amount of the weight of the crushed C&D waste. Generally, the problem of fine fraction has not been much analysed until now. For this reason, in this work, an innovative mortar mix design for using recycled sand from C&D has been analysed, by partial replacement of standardized sand (SS) with recycled sand (RS) or washed recycled sand (RSW) and by using a fixed w/c ratio equal to 0.5. The main aim of this research has been to investigate if washing and sieving of recycled aggregates can improve the quality of the recycled aggregate. Analyses allowed concluding that the quality of the recycled aggregate could be improved by washing and sieving of recycled aggregates and that in any case the bending strength and the fracture energy increase or decrease simultaneously.